The invention concerns a process for examining of membrane enclosed biocompartments, wherein the biocompartments are arranged in a micro-flow chamber. This micro-flow chamber is subject to the through-flow of a culture medium containing an active agent and which is in contact with the said biocompartments and possibly has an effect thereon. Further, the pH value of the culture medium present in the micro-flow chamber can be measured. In this arrangement, the biocompartments can hold, for instance, biological cells, microorganisms (fungi, bacteria), biochemical compartments and/or mitochondria.
EP 0 394 406 B1 discloses a process of the type known in the art, in which living, biological cells are placed in a micro-flow chamber being subjected to the through-flow of a culture medium and which chamber has a silicon sensor on its bottom. A reference electrode is provided in the micro-flow chamber, which is in continual contact with the culture medium. In the case of this previously known process, in a first process step, the through-flow of the culture medium is stopped in the micro-flow chamber. Under these circumstances, the pH value, serving as a metabolic indicator of substance change in the culture medium residing in the micro-flow chamber, is determined by measurement of the electrical potential between the silicon-sensor and a reference electrode. With this process, it is possible to measure, for instance, the action of a cell-affecting agent on the metabolism of the cells. A detriment, however, lies in the fact, that the process enables only one determination in regard to a yield of acid metabolic products, while other changes caused by the metabolism of the cells are not given consideration.
DE 44 17 078 A1 makes known a process wherein biological cells in a micro-flow chamber are simultaneously examined by means of a plurality of different micro-sensors. As this is carried out, in addition to the acidification, at the same time the respiration of the cells in the culture medium is monitored, which enables a more exact investigation of the action on the cells of an agent contained in the culture medium. This procedure, however, has the disadvantage, that the measured values for pH and oxygen content are determined at different places and thus of differing biological cells present in the micro-flow chamber. Cell cultures, cell divisions, tissues and the like which are to undergo examination as biological material are, however, often heterogenous, that is, different cells can yield different signals. In this known procedure, on this account, imprecisions in the investigation of an agent in the culture medium can occur if the pH value and/or the oxygen content at the points of determination of the sensors deviate in pH and oxygen content from one another.